Force transmission devices for applications in motor vehicles are known in various configurations. They comprise a hydrodynamic component and an actuatable clutch device for circumventing the power transmission through the hydrodynamic component. The flow routing within the force transmission device is performed, so that the hydrodynamic component flows through in a centrifugal or centripetal direction. Thus, in one operating mode of the hydrodynamic component, the flow medium is not only turned over in the operating cavity, but it is also run through an external cooling loop outside of the hydrodynamic component. Furthermore, the operating medium also remains in the force transmission device in a bridged condition of the force transmission device and it is run through an external loop for cooling purposes. The routing is typically performed through the intermediary space defined by the housing of the force transmission device and the outer circumference of the hydrodynamic component, wherein, in particular, in embodiments in a two-channel configuration, in which the force transmission device is characterized by at least two connections and the operation of the actuation device of the actuatable clutch is performed by controlling the pressure difference between the two connections, the flow medium is run through the actuatable clutch device for cooling purposes. On the other hand, embodiments in three-channel configurations are characterized in that a separate chamber loadable with pressure medium is associated with the actuation device, which chamber provides free adjustability of the actuation pressure through a third connection. The actuatable clutch device is typically configured as a friction locking clutch, wherein the configuration is performed in disk construction and thus as a multidisk clutch. The slipping operation, however, leads to strong heating and loading of the friction liners. Insufficient cooling and abrasion and breakdown components of the friction liners and waste products in the flow medium furthermore degrade the function and reliability of the actuatable clutch device.
From the printed document DE 103 50 935 A1, an embodiment of a force transmission device is known, in which measures are taken in order to restrict the oil flow in the force transmission device in certain portions, so that a general pressure increase in the housing is created. In the first solution described in the embodiment, at least one additional resistance element for the oil flow is disposed between the inside of the converter housing and the outer circumference of the turbine shell, which causes the oil flow not to be able to flow through the cavity without restriction. The additional element is formed by the actuatable clutch device itself. Furthermore, alternatively or additionally, a reinforcement of the oil flow is possible through configuring channels in at least one of the disks.
In an embodiment as a three-channel converter, as described in WO 2007/079713 A1, a pressure tight additional wall is provided, which is disposed on the side of the piston element and which faces the first cavity which forms a gap between the piston element and the additional wall. The additional wall is placed substantially oil tight against the disks facing the piston and simultaneously facilitates a hydraulic separation from the adjacent pressure cavities, in particular the intermediary space and the separate cavity which can be loaded with operating means.
The printed document WO 2007/048505 A1 discloses an embodiment, in which the disks of the actuatable clutch device, which can be operated by a piston element, route hydraulic fluid along the clutch disks to a torsion damper. The hydraulic fluid which is routed through the pressure cavity for the actuatable clutch device is subsequently routed along the clutch disks into the interior cavity of the converter, which provides highly efficient cooling.
An embodiment of a force transmission device of this type is known from the printed document DE 197 22 151 A1. The force transmission device comprises an input and an output, a hydrodynamic component disposed between input and output, comprising at least a pump shell and a turbine shell forming an operating cavity in combination, and an actuatable clutch device for at least partially bridging the hydrodynamic component, comprising a first clutch component connected to the input and a second clutch component at least indirectly connected with the output. A vibration damper is disposed in a force flow direction behind the actuatable clutch device and the hydrodynamic component. The force transmission device furthermore comprises a housing coupled to the input or to an element connected torque proof to the input, and coupled to the pump shell, which housing encloses the actuatable clutch device and the vibration damper and forms an intermediary space. Means for forming a flow cycle between the operating cavity and the intermediary space are provided, wherein means for generating an oriented flow through the actuatable clutch device are disposed in the intermediary space, which means conduct the flow medium directly into the portion of the actuatable clutch device through forming a channel, which channel is implemented through the connection of the second clutch component with the vibration damper. The operating medium flowing through the force transmission device exits at the outer circumference of the actuatable clutch device after going through a deflection. The disadvantage of this embodiment is that not the entire operating means is conducted through the actuatable clutch device, but some is run through the damper.